1. Field of the Invention
The present invention relates to position indicating and control apparatus. More specifically, the present invention is directed to a position indicating and control apparatus utilizing Hall effect elements for translating a shaft position to a corresponding signal.
2. Description of the Prior Art
Prior art indicating and control apparatus for translating a shaft motion to digital signals have usually involved mechanical switches which operate in conjunction with brushes contacting a so-called code converter plate having coded conductive patterns thereon. Such indicating and control devices are shown in U.S. Pat. Nos. 2,766,445 and 2,935,583. The use of magnets for transmitting signals through a non-magnetic wall is shown in U.S. Pat. Nos. 2,908,778 and 2,935,583. The use of selectively positionable magnets for actuating Hall effect elements or devices is found in the prior art in U.S. Pat. Nos. 4,107,604 and 4,054,860. In order to provide an indicating device utilizing Hall effect devices which affords the protection of closed housings separating the Hall effect elements from the actuating magnets while providing a coded operation for conversion from the rotary motion of a control knob to a digital output of the Hall effect signals is a desirable apparatus having significant utility in specific combination with fluid devices utilizing fluid-tight chambers.